arraylist - Geting different outputs in and out of a while loop

Question

I fill an ArrayList in a while loop via the constructor of the object. See for yourself

int z = 0;
         while(z < 30)
        {
            if(z >= 0 && z <= 4)
            {
            SKT.add(z,new SkeletonTile("0","0","0","1"));
            System.out.println(SKT.get(z).toString());
            }
            else if(z >= 5 && z <= 9)
            {
            SKT.add(z,new SkeletonTile("0","0","1","0"));
            System.out.println(SKT.get(z).toString());
            }
            else if(z >= 10 && z <= 19)
            {
            SKT.add(z,new SkeletonTile("0","1","0","0"));
            System.out.println(SKT.get(z).toString());
            }
            else if(z >= 20 && z <= 29)
            {
            SKT.add(z,new SkeletonTile("1","0","0","0"));
            System.out.println(SKT.get(z).toString());
            }
            z++;
        }

I am getting the right output inside the while loop which should be :

0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0

But when i scan the arraylist just above of the while loop (inside the same method of course) i get this output : 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0

I dont know why the values change without doing something.. All the 1s are in the first spot.

Answer 1

等待大神答复